Sash balance



- Nov. 18, 1969 P. SKOLNIK SASH BALANCE Filed Feb. 8, 1968 2 Sheets-Sheet 2 INV ENTOR BYJM., Milt-M WW ATTORNEYS United States Patent Office Patented Nov. 18, 1969 3,478,384,v SASH BALANCE Phil Skolnik, 13131 Almeda Road, Houston, Tex. 77045 Filed Feb. 8, 1968, Ser. No. 704,017 Int. Cl. E05d 13/12 U.S. Cl. 16--197 7 Claims ABSTRACT 0F THE DISCLOSURE A sash balance comprising a vertical hollow housing containing a spiral torsion springvixedly connected to the housing at its upper end. A projecting shaft secured to the lower end of the spring has a slot embracing a concentric spiral rod in mating relation to cause the shaft to be rotated by axial motion ofthe rod. A connector is xedly connected to the lower end of the housing. The connector and the shaft include snap-acting, interengaging means for rotatably connecting the shaft andthe second connector upon predeterminedrelative axial closing movement between them." l

Th'e lower end of the spiral rod includes a stud received within a slot in a clip adapted to be secured to the window sash. The clip lis bent away from the rod adjacent an open end of the slot to prevent separation of the stud from" the clip. A

BACKGROUND OF INVENTION This invention relates to window sash balances and improvements therefor, and in particular to a window sash balance of the loaded spiral torsion spring type having improved assembly features. v

In installing window sash units it is common to provide sash balances to assist inlifting the sash and for maintaining it in the last position to which it was moved. One form of sash balance is the so-called spiral sash balance utilizing a spiral torsion spring. In such a balance a spiral torsion spring is positioned Ywithin an axially extending housing secured to the vusual window jamb, with the upper end of the spring fixedly connected to the upper end of the housing. A spiral rod matingly engages a spring anchor secured to the lower end of the spring projecting downwardly therefrom, and is ,secured to the window sash. Vertical lowering and raising of the window sash, moving the spiral rod axially, causes the spring anchor to load and unload the spring respectively.

Although such spiral sash balances offer` significant operational advantages over several other forms of sash balance, serious manufacturing problems commonly arise in the assembly of the various component parts of spiral sash balances.

For example, there have been problems hitherto in providing an uncomplicated connected between the lower end of the spring andthe spiralrod to provide for loading of the spring and for combining this connection with a connection to the housing to locate spring against axial motion but permit rotational movement. Various relatively complicated lower end connection assemblies have been proposed but in general they require numerous assembly steps involving appreciable expense.

Other problems have arisen in the provision of a suitable connection between the free extremity of the spiral rod and the window sash in that it has sometimes been possible during lifting motion for the rod and window sash to become disengaged, thereby rendering the sash balance ineffective.

SUMMARY OF INVENTION It is therefore a general object of the invention to provide a window sash balance of the spiral spring type intended to overcome or minimize problems of the type previously noted.

It is a particular object of the invention to provide a spiral sash balance adapted for ready assembly of its component parts.

It is a further object of the invention to provide a spiral sash balance having an axially fixed but rotational connection between one end of the spring and the adjacent end of the housing, which is of particularly simple construction.

It is yet another object of the invention to provide a spiral sash balance in which the possibility that the sash balance operating rod may inadvertently become separated from the window sash is obviated or minimized.

A sash balance in accordance with one preferred embodiment of the invention includes a hollow housing extending axially in a vertical direction. An axially extending spiral torsion spring positioned within the housing is fixedly connected at one axial end to an adjacent one axial end of the housing by a rst connector. An axially extending spiral rod positioned within the spring has one free end of the rod projecting outwardly of the other end of the spring. A tubular shaft fixedly connected with the other end of the spring includes a free extremity projecting outwardly of the spring. The shaft further includes a generally rectangular slot positioned generally centrally of the shaft extending axially therethrough. The slot embraces the spiral rod in mating relation to cause the shaft to be rotated by the rod upon relative axial motion between the rod and the shaft. A second connector is fxedly connected to the other end of the housing and includes an axial bore slidably receiving portions of the shaft adjacent the free extremity thereof. The second connector and the shaft include snap-acting, interengaging means for rotatably connecting the shaft and the second connector upon predetermined relative axial closing movement between them, and for thereafter preventing subsequent axial separation of the shaft and the second connector. In this manner the spring may be axially fixed and rotatably connected with the housing at one end by simple axial pushing movements only.

Also significant is the provision of a special clip for preventing inadvertent separation of the axial rod from the window sash. For this purpose the rod adjacent its free extremity is provided with a at portion having a headed stud projecting perpendicularly therefrom. The stud is received within an axially extending slot in a clip adapted to be secured to the window sash. The slot extends axially of the rod and has a closed extremity abutting the stud beneath the head on a side thereof remote from the free extremity of the rod. Other portions of the clip adjacent an open extremity of the slot are bent away from the flat portion of the rod to prevent axial separation of the head of the stud from the slot.

THE DRAWINGS A preferred embodiment of the invention is illustrated in the accompanying drawings in which:

FIGURE l is a cross-sectional, side view of a window sash balance according to one preferred embodiment of the'invention, shown installed in a portion of a sash window assembly;

FIGURE 2 is a cross-sectional side view on an expanded scale of a lower connection assembly forming a part of the window sash balance shown in FIGURE 1, taken on the line 2-2 in FIGURE 3;

FIGURE 3 is `a cross-sectional side view of the lower connection assembly shown in FIGURE 2 taken at right angles thereto along the line 3--3 therein;

FIGURE 4 is a cross-sectional end view of the lower connection assembly shown in FIGURE 2 taken along the lines 4-4 therein;

FIGURE 5 is a cross-sectional end view of a part of the lower end connection assembly shown in FIGURE 3 taken along the lines 5 5 therein;

FIGURE 6 is a side view on an enlarged scale of a rod retaining clip forming a part of the window sash balance shown in FIGURE l;

FIGURE 7 is an end view of a portion of the rod retaining clip shown in FIGURE 6 taken along the lines 7-7 therein;

FIGURE 8 is an exploded perspective view of a shaft and lower end connector forming a part of the lower connection assembly shown in FIGURE 2; and

FIGURE 9 is an exploded perspective view of the rod retaining clip shown in FIGURE 6.

DETAILED DESCRIPTION Structure Referring to FIGURE 1 of the drawings, a sash balance 2 according to a preferred embodiment of the invention is there shown, installed between conventional window jamb structure 4 and conventional window sash structure 6. A more detailed description of the mounting of the sash unit in the surrounding window structure may be obtained by reference to my U.S. Patent 3,271,812.

The sash unit 2 includes a vertically extending housing 8 of suitable light, rigid material such as aluminum, or suitable plastics. The housing 8 comprises an open ended rigid tube of generally U-shaped configuration (FIGURE 5) having a semicircular central section 10 blending into two fiat wall portions 12 spaced apart with their free extremities defining an opening 14 facing toward the adjacent window jarnb structure 4. Each wall portion 12 has an inwardly directed, vertically extending beading 15 provided along its free edge.

Positioned within the interior of the housing 8 is an axially extending, coiled torsion spring 16 of the fiat wire type. The spring 16 is fixedly connected with the housing 8 adjacent the upper end thereof by a top or first connector 18 made of nylon. The first connector 18 includes an axially extending central body 20 having an exterior peripheral surface shaped to fit slidingly and snugly within and against the interior of the housing 8. Across the opening 14 of the housing 8, the central body 20 has a fiat peripheral face facing towards the adjacent portions of the window jamb 4, Aligned, horizontally disposed apertures are provided in the central body 20 and in adjacent portions of the housing 8 to receive an elongate connector 22, such as a screw for securing the upper end of the housing to the window jamb 4.

To limit motion of the central body 20 into the open upper end of the housing 8 upon assembly, a rim 24 shaped to conform to the exterior profile of the housing 8 is provided integrally on the central body 20 at the upper end thereof. On assembly the rim 24 moves into t abutting contact with the upper end of the housing 8 to limit relative axial closing motion between them.

The spring 16 is fixedly and anti-rotationally secured to the first connector 18 by a locating tube 26 concentric and integral with the main body 20, depending therefrom. At its lower end the locating tube 26 has an exterior peripheral fuiste-conical end portion 28 having a minimum diameter less than the interior diameter of the spring 16. The portion 28 blends into a main peripheral portion 29 of the locating tube 26, which is of greater diameter than the spring 16. The locating tube 26 is forced into the spring 16 so that the latter becomes radially expanded about the main portion 29 into firm, gripping Contact therewith. An axially extending circular bore 30 extends entirely through the first connector 18.

A spiral rod 34 is positioned concentrically within the spring 16 extending downwardly and outwardly thereof below the housing 8. The spiral rod 34 is formed from longitudinally extending, fiat sheet material of uniform width and thickness, twisted into a regular, spiral configuration. At its upper end, the rod 34 may extend partially into'the bore 30 of the first connector" ina retracted condition ofthe rod. At its lower end projecting below the housing 8, the spiral rod is provided with a attened end portion 38 connected by a clip 39 to the window sash structure 6. As the window is yraised and lowered it causes corresponding axial motion of the rod 34.

To operatively connect the spiral rod 34 with the spring 16 and with the housing 8, a lower end connection assembly generally designated 40 (FIGURES 2 and 3) is provided. The connection assembly includes a shaft member 42 and a lower end or second connector 44 (FIG- URE 8) both fabricated of nylon.

The shaft member 42 includes locating tube 45 having end and main portions 46 and 47 of similar construction to the previously described locating tube 26 of the first connector. The locating tube enters and is fixedly secured to the lower end of the spring 16 in the same manner as the locating tube 26. Integral with and extending downwardly from the locating tube 45 is a concentric annular collar 48 having one annular, radially extending, fiat surface 50 abutting the adjacent end parts of the spring 16. The collar 48 also includes an annular, downwardly and radially inwardly inclined, slant face 52. Extending downwardly from the slant face 52 is a bearing portionr54 of generally the same external diameter as the main portion 47 of the locating tube 45 concentric therewith. A boss 56 concentric and integral with the bearing portion 54 is integrally provided at the lower end thereof. The boss 56 includes a maximum diameter, axially extending, peripherally facing rim 58 of generally the same diameter as the maximum diameter of the previously menttioned collar 48, and a frusto-conical, downwardly directed portion 60 integral with and extending downwardly and inwardly from the rim 58.

The shaft member 42 also includes an internal bore 62 extending axially through the shaft member surrounding the spiral rod 34 which passes through the shaft member with ample clearance. Internally of the bore 62, axially adjacent the bearing portion 54, is provided an internally constricted region 64 (FIGURE 4). The constricted region 64 includes a generally rectangular, axially extending slot 66 loosely embracing the spiral rod 34. The slot 66 has a major side 68 a small amount greater than the width of the sheet material from which the spiral rod is formed and a minor side 7 0 a small amount greater than the thickness of the sheet material of which the spiral rod 34 is formed. As the rod 34 is advanced axially of the shaft member 42 by raising and lowering of the sash window, the spiral rod 34 contacts the edges of the slot to cause rotational motion of the shaft thereby causing corresponding twisting and untwisting of the spring 16.

To locate the shaft member 42 in fixed axial relation to the housing 8 for rotation relative thereto, the previously mentioned second connector 44 is provided. The second connector 44 includes an axially extending main body 80 having an external peripheral face shaped to be slid axially into the open lower end of the housing 8 in snug abutting contact with the interior thereof. Integral with the lower end of the central body is a peripherally extending rim 82 having the same peripheral profile as the housing S. The rirn 82 abuts the adjacent lower end edges of the housing 8 once the second connector 44 is inserted into the housing 8 to limit further internal motion of the second connector into the housing.

To facilitate mounting the second connector 44 in the lower end of the housing 8, the connector is provided with snap-engaging, projecting ears 84 positioned on opposite sides of the central body 8() on the peripheral surface adj acent the upper end thereof. Each of the ears 84 is aligned with one of two generally closed rectangular cut-out openings 86 (FIGURE 3) extending through each of the fiat side wall portions 12 of the housing 8. The openings 86 are positioned adjacent and spaced a short distance from the lower end of the housing 8 and spaced a short distance away from the adjacent free vertical edges of the wall portions 12. Each ear 84 further includes a wedging surface 88 inclined downwardly and away from the adjacent peripheral surface of the body 80 anda locking surface 90 disposed perpendicularly to adjacent portions of the peripheral surface'of vthe main body 80. On assembly, as the second connector unit 44 is pressed into the open lower end of the housing 8, the wedgingsurfaces 88 of the ears 84 resiliently distend apart the adjacent side wall portions 12 of the housing 8. As the rim 82 moves into abutting Contact with the end of the housing 8, the ears 84 concurrently enter the openings 86 so that the adjacent portions of the housing snap closely about them. The locking surfaces 90 then prevent subsequent separation of the second connector 44 from the housing.

Inside the central body 80 of the second connector 44 is an axially extending interior bore 92 (FIGURES 2, 3 and 8) of sufficient diameter to snugly but rotatably receive the maximum diameter rim 58 of the boss 56 of the shaft member 42. A resiliently deformable annular flange 94 integral with the upper end of the body 80 projecting inwardly of the bore 92 is provided. The flange 94 is resiliently deformable and includes a downwardly and radially inwardly inclined slant face 96 facing upwardly and a lower, flat, radially extending face 98. The flange 94 extends peripherally around lthe interior of the bore 92 ex cept for a small radial cut-.out portion 100 provided to facilitate resilient deformation of the flange.'

l During assembly of the Vsash balance which will be described inv more detail hereinafter, the shaft member 42 and the second connector 44 are pressed relatively together so that the boss 56 enters the bore 92 and resiliently deforms the flange 94 downwardly until the rim 58 has passed below the flange. The flange then snaps back into position above the boss V56 adjacent the bearing portion S4 to prevent subsequent axial separation of the shaft 42, thus locating it axially relative to the second connector 44 but permitting relative rotational movement. It will be appreciated that the boss 56 and flange 94 thus constitute snap action interengaging portions facilitating assembly of the sash balance unit by simple, axially directed pressure.

As the window sash 6 is lowered relative to the window jamb 4, axial motion of the rod 34 through the shaft member 42 causes the latter to be rotated in such a direction as to increase the torsional loading of the spring 16. When the sash is raised, expansion of the spring 16 releasing torsional energy stored in the spring assists in raising the window sash against gravity. In any position, the window sash is held against dropping under the effect of gravity by the resistance to further torsional deflection of the spring 16. l

Aspreviously mentioned, the lower end of the spiral rod 34 is secured to the window sash by the clip 39 (FIG- URES 6v and 7). The clip 39 is formed of sheet metal and includes vertically extending upper and lower flanges 1 and 102 respectively connected by a horizontal, intermediate web 104. The vertical flange 101 is adapted to abut an adjacent vertical portion of the window sash structure 6 and is fixedly connected thereto by a suitable elongate connector 108 such as, for example, a screw.

The lower flange 102 includes an intermediate portion 110 disposed in parallel abutting relation to the previously mentioned flattened portion 38 at the free extremity of the spiral rod. A'lower portion 112 integral with the intermediate" portion 110 extends downwardly therefrom and is deflected away from the adjacent portion 38 of the rod. To secure the rod and clip together, a stud 114 secured to the end portion 38 passes through an axially extending slot 116 in the lower flange, of sufficient width to matingly, slidingly receive the stud 114. The slot 116 has a closed upper extremity 118 in abutting contact with the stud. A head 120 of greater diameter than the stud is disposed in overlapping relation to the adjacent areas of the intermediate portion 110 of the lower flange. The slot 116 further includes an open lower extremity to provide for entry of the stud into the slot on assembly before the upper flange 101 is secured to the sash 6.

On assembly, the clip is engaged either by lengthwise bending of the rod portion 38 to interengage the stud 114 with the clip on the sash; or, if preferred, the clip canrbe slid over the stud prior to securing the upper flange 101 to the adjacent sash portion 6. Axial separation of the lower flange 102 from the stud 114 is prevented by deflecting the lower portions 112 away from the rod portion 38 so that travel of the head 120 along the slot is prevented once the unit has been assembled on the sash, thus inclining the portions 112 in blocking relation against the head.

Assembly In the assembly of the sash balance, the locating tube 26 is forced axially into the upper end of the spring 16 to secure the first connector 18 to the spring. Similarly the locating tube 45 is forced axially into the lower end of the spring 16 to secure the shaft member 42 to the spring. The spring 16 is then fed axially into the housing 8 through the open upper end thereof until the rim 24 of the first connector 18 comes into abutting contact with the upper edge of the housing 8. At this time the boss 56 of the shaft member 42 will be located adjacent the lower end of the housing 8. The second connector 44 is then forced axially into the lower end of the housing 8 while holding the boss 56 in fixed position. This causes the flange 94 to pass over the boss 56 to secure the shaft member 42 and second connector 44 together for relative rotation. At the same time the ears 84 of the second connector 44 are snapped into fixed connection with the housing 8 to secure the second connector to the housing. The spiral rod is slid through the opening 66 in the shaft member 42 into the spring. The lower flange of the clip 39 is slid along the stud 114 to secure the clip to the spiral rod. An opening 122 in the end of the spiral rod may be engaged by a tool to aid in engagement with the clip.

The upper end of the housing may be secured by the connector 20 to the window jamb 4, and the upper flange of the clip 39 should be secured to the window sash unless it has been attached as described above.

SUMMARY OF ADVANTAGES In following the construction of the present invention a sash balance having certain significant advantages is provided.

Particularly significant is the provision of connections between all the elements of the sash balance which may be. assembled by simple axial pushing movement, thereby producing an uncomplicated sash balance suitable for low-cost production.

In this regard the snap-engaging connection provided between the shaftmember and the second connector affords a simple but effective connection between the spring, the spiral rod and the lower end of the housing to facilitate twisting of the spring under the action of the spiral rod.

Also significant is the provision of the clip specially configured to entrap the head of the stud once the clip has been secured to the adjacent window sash so that subsequent separation of the window sash from the spiral operating rod is prevented.

Although the invention has been described with reference to a preferred embodiment, it will be appreciated by those skilled in the art that numerous additions, deletions, substitutions, modifications and other changes not specifically described, may be made which will fall within the spirit of the invention.

I claim:

1. A sash balance for use with a window sash, said sash balance comprising,

. an axially extending hollow housing,

an axially extending spiral torsion spring positioned within said housing,

an axially extending spiral rod positioned within said spring projecting outwardly of one end thereof, an annular shaft fixedly connected with said one end of said spring projecting outwardly thereof, said shaft including,

axially extending slot means positioned generally centrally of said shaft and embracing said spiral rod in mating relation thereto to cause said shaft to be rotated by said rod upon relative axial motion between said rod and said shaft; a connector fixedly connected to said one end of housing, said connector having an axial bore slideably receiving portions of said shaft; said connector and said shaft including,

snap acting, inter-engaging means for rotatably connecting said shaft and said connector upon predetermined relative axial closing movement therebetween and for thereafter preventing subsequent axial separation of said shaft and said connector. 2. A sash balance as defined in claim 1 wherein, said bore and said shaft are of circular cross-section and are of relatively larger and smaller diameters, said inter-engaging portions including,

a boss secured to said free extremely of said shaft concentric therewith, said boss being generally frusto-conical and facing toward said second connector with said boss having a maximum diameter slightly less than said bore to be rotatably received therein; and

a flange fixedly secured to and extending about the interior of said bore, said flange having an interior diameter smaller than said maximum diameter of said boss, said flange being resiliently deformable in one direction away from said shaft to permit said boss to be pushed entirely past said flange in said one direction into an engaged relation but to prevent axial separation of said boss from said flange thereafter in a reverse axial direction.

3. A sash balance as defined in claim 2 further including a raised annular collar fixedly secured to said shaft spaced axially from said boss on an opposite side of said ange from said boss when said boss is in engaged relation with said second flange.

4. A sash balance as defined in claim 2 wherein,

one end of said housing is open,

said connector further including,

an axially extending peripheral face shaped to be slid axially into said open one end of said housing in snug abutting relation thereto,

a peripherally extending raised rim at an outer axial end of said peripheral face abuttingly contacting a radial end surface of said housing at said one end thereof to limit axial motion of said connector into said housing;

said peripheral face of said connector and adjacent prtions of said housing including,

snap acting, second inter-engaging means for fixedly connecting said connector and said housing upon predetermined relative axial closing movement therebetween and for thereafter preventing subsequent axial separation of said housing and said connector.

5. A sash balance as defined in claim 4 wherein,

said second inter-engaging means includes,

at least one opening in said housing adjacent and spaced axially from said one end thereof,

at least one ear projecting from said peripheral surface of said connector, said ear including, a forward surface inclined axially toward said one end of said housing to resiliently deflect adjacent portions of said housing away from said peripheral surface upon movement of said connector into said housing; a rear surface extending perpendicularly from said peripheral surface,

said ear snapping into said opening upon arrival thereat with said rear surface preventing withdrawal of said connector from said housing.

6. A sash balance as defined in claim 1 wherein, said spiral rod adjacent an extremity thereof outward of said spring further includes,V

an axially extending at portion;

a stud projecting perpendicularly from said fiat portion;

a head on the free extremity of said stud said head being of greater diameter than said stud;

a clip adapted to be secured to adjacent portions of the window sash, said clip including,

a flat member having,

one surface abuttingly contacting said flat portion of said spiral rod,

another surface of said flat member abuttingly contacting the adjacent surface of said head;

an axially extending slot in said hat member havan open end facing toward said free extremity of said spiral rod, said slot embracing said stud but being of smaller diameter than said head, said slot further including a closed extremity abutting said stud on a side thereof remote from said free extremity of said rod; and

foot portions on said flat member on a side of said stud adjacent said free extremity of said rod, said foot portions inclined away from said rod preventing separation of said stud from said clip.

7. A retaining clip for securing a spiral rod forming part of a spiral spring type sash balance to a window sash, the spiral rod further including a free extremity having a flat portion generally parallel to adjacent side portions of the windo-w sash with a headed pin projecting perpendicularly from the flat portion, said retaining clip comprising;

a first member adapted to be secured to the adjacent side portions of the window sash,

a second member connected to said first member, said second member including,

a slot having one open end to permit the second member to be slid between said at portion of said spiral rod and the headed portion of said pm,

a first portion positioned around said headed pin when said clip is in engaged relation in said slot; and

a second portion adjacent said open end of said slot diverging away from said spiral rod to block release of said headed pin from said slot.

References Cited UNITED STATES PATENTS 3,271,812 9/1966 Skolnik 16-197 3,286,301v 11/1966 Skolnik 16-197 DONALD A. GRIFFIN, Primary Examiner 

